Polyester resins are widely used in reinforced plastics, paints, films, and resins for molding, and are also used as fabric materials to produce clothing due to characteristics of superior heat resistance, mechanical strength and elastic strength.
The use of polyester resins in the fields of interior building materials or molded sign panels is increasing because of the characteristic physical properties. However, polyester resins have lower heat resistance than other polymer materials, for example acrylic materials or polycarbonate materials, and thus there is a problem that polyester resins are not suitable for exterior building subject to large seasonal temperature changes.
Polycarbonate resins are used in a variety of building materials and housings for electronic products, packaging materials, cases, boxes, and interior/exterior building materials due to excellent properties of impact resistance and heat resistance. Demands for such polycarbonate resins are increasing because of these properties. However, problems with their use may include discoloration or cracking of polycarbonate products due to cleaners, cosmetics, hand sanitizers, or various household chemicals.
There have been many attempts to solve the problems of polyester resins and polycarbonate resins, and studies on blending of the polyester resins with the polycarbonate resins have been conducted.
Further, a technique of improving impact resistance and heat resistance by blending an acrylonitrile-butadiene-styrene-based graft copolymer (ABS) with a polycarbonate resin has been developed, but the product is not an environmentally friendly biomass product. Since the polyester resin and the polycarbonate resin are different in terms of melting point and molecular structure, it is difficult to improve heat resistance only by simple blending the two. Further, many methods have been used in order to improve chemical resistance while maintaining the mechanical properties of polycarbonate, particularly heat resistance, but the improvement of chemical resistance has not progressed enough to be industrially practical. Additionally, a method of further blending the two with other materials has been attempted in order to improve heat resistance and chemical resistance, but this did not obtain satisfactory chemical resistance.
Among automobile interior materials, PC/ABS (Polycarbonate/ABS) is an engineering plastic generally used for center fascias. By combining the excellent heat resistance, impact resistance, and self-extinguishing properties of PC and processability and economic advantages of ABS, PC/ABS has been developed for center fascias that require high heat resistance, impact resistance, and painting properties. In terms of chemical resistance, PC/ABS is susceptible to most chemicals, such as aromatic hydrocarbons, ketones, aldehydes, alcohols, and terpenes (limonene, etc.). When PC/ABS is directly exposed to these chemicals for a long period of time, discoloration, swelling, and cracking occur and deteriorate the value of the product. Further, the material has safety problems if used as a material in a head impact zone. Therefore, many studies have been conducted to prepare a polymer composition having superior chemical resistance to the conventional PC/ABS. For example, it was reported that polyolefin-based resins having excellent chemical resistance were mixed and used in order to improve chemical resistance of PC/ABS. However, there are problems such that a block copolymer must be used as a compatibilizer in order to improve compatibility of incompatible materials, and phase separation occurs when practically applied, leading to a rapid reduction in mechanical properties.
Accordingly, there is a need for a chemical resistant polymer composition for center fascia which is capable of providing a resin having excellent resistance to environmental stress cracking against car air fresheners, and improved heat resistance and/or impact resistance.